.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
ia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary.pdf 1
Dosage form consist of;
Active Pharmaceutical ingredient (API) and Excipients
stuvia.com/user/gabrieluckyhttp10/22/2026,
.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary 1
,.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
ia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary.pdf 1
Formulation of Gels
Gels are used for drug delivery for several administration routes e.g. oral, topical, vaginal,
and rectal administration.
Gels can be clear formulations when all of the particles completely dissolve in the
dispersing medium, however some gels will be turbid if this does not occur. Clear gels are
preferred by patients.
Gels are made using gelling agents that undergo a high degree of cross-linking or
association when hydrated and dispersed in the dispersing medium, or when dissolved in
the dispersing medium. This cross-linking or association of the dispersed phase will alter the
viscosity of the dispersing medium. The movement of the dispersing medium is restricted by
the dispersed phase, and the viscosity is increased.
* If the gel contains small discrete particles, the gel is called a two-phase system.
* If the gel does not appear to have discrete particles, it is called as a one-phase system.
* If a gel is semisolid upon standing but liquefies when shaken then the system is thixotropic.
stuvia.com/user/gabrieluckyhttp10/22/2026,
.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
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2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary 1
,.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
ia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
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2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary.pdf 1
Common Gelling agents
Some of the common gelling agents are acacia, alginic acid, bentonite, Carbopols® (now
known as carbomers), carboxymethylcellulose. ethylcellulose, gelatin,
hydroxyethylcellulose, hydroxypropyl cellulose, magnesium aluminum silicate
(Veegum®), methylcellulose, poloxamers (Pluronics®), polyvinyl alcohol, sodium alginate,
tragacanth, and xanthan gum. Though each gelling agent has some unique properties,
there are some generalizations that can be made.
1. Addition of the gelling agent in a haphazard manner will result in clumping of the gelling
agent. The outer molecules of the gelling agent contact the medium first and hydrate
forming a surface layer that is more difficult for the medium to penetrate. The clumps will
ultimately hydrate, but it will take more time. Therefore when adding a gelling agent to the
dispersion medium it is more efficient to sieve the agent onto the surface of the medium a
little at a time as the medium is stirring. If a sieve is not available just make sure that it is lump
free powder and sprinkle small amounts onto the surface with thorough mixing/dispersion
after each addition. Using glycerol as a wetting agent will sometimes minimize clump
formation.
stuvia.com/user/gabrieluckyhttp10/22/2026,
.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
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2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary 1
,.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
ia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary.pdf 1
2. Some gelling agents are more soluble in cold water than in hot water. Poloxamers have
better solubility in cold water while bentonite and gelatin are more soluble in hot water.
3. Some gelling agents (carbomers) require a "neutralizer" or a pH adjusting chemical to
create the gel after the gelling agent has been wetted in the dispersing medium.
4. Most gelling agents require 24-48 hours to completely hydrate and reach maximum
viscosity and clarity.
5. Gelling agents are used in concentrations of 0.5% up to 10% depending on the agent.
6. It is easier to add the active drug before the gel is formed if the drug doesn't interfere
with the gel formation.
7. Only Carbopol® 934P, methylcellulose, hydroxypropyl methylcellulose, and sodium
carboxymethylcellulose are recommended for oral administration.
stuvia.com/user/gabrieluckyhttp10/22/2026,
.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary 1
ia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary.pdf 1
Dosage form consist of;
Active Pharmaceutical ingredient (API) and Excipients
stuvia.com/user/gabrieluckyhttp10/22/2026,
.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary 1
,.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
ia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary.pdf 1
Formulation of Gels
Gels are used for drug delivery for several administration routes e.g. oral, topical, vaginal,
and rectal administration.
Gels can be clear formulations when all of the particles completely dissolve in the
dispersing medium, however some gels will be turbid if this does not occur. Clear gels are
preferred by patients.
Gels are made using gelling agents that undergo a high degree of cross-linking or
association when hydrated and dispersed in the dispersing medium, or when dissolved in
the dispersing medium. This cross-linking or association of the dispersed phase will alter the
viscosity of the dispersing medium. The movement of the dispersing medium is restricted by
the dispersed phase, and the viscosity is increased.
* If the gel contains small discrete particles, the gel is called a two-phase system.
* If the gel does not appear to have discrete particles, it is called as a one-phase system.
* If a gel is semisolid upon standing but liquefies when shaken then the system is thixotropic.
stuvia.com/user/gabrieluckyhttp10/22/2026,
.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary 1
,.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
ia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary.pdf 1
Common Gelling agents
Some of the common gelling agents are acacia, alginic acid, bentonite, Carbopols® (now
known as carbomers), carboxymethylcellulose. ethylcellulose, gelatin,
hydroxyethylcellulose, hydroxypropyl cellulose, magnesium aluminum silicate
(Veegum®), methylcellulose, poloxamers (Pluronics®), polyvinyl alcohol, sodium alginate,
tragacanth, and xanthan gum. Though each gelling agent has some unique properties,
there are some generalizations that can be made.
1. Addition of the gelling agent in a haphazard manner will result in clumping of the gelling
agent. The outer molecules of the gelling agent contact the medium first and hydrate
forming a surface layer that is more difficult for the medium to penetrate. The clumps will
ultimately hydrate, but it will take more time. Therefore when adding a gelling agent to the
dispersion medium it is more efficient to sieve the agent onto the surface of the medium a
little at a time as the medium is stirring. If a sieve is not available just make sure that it is lump
free powder and sprinkle small amounts onto the surface with thorough mixing/dispersion
after each addition. Using glycerol as a wetting agent will sometimes minimize clump
formation.
stuvia.com/user/gabrieluckyhttp10/22/2026,
.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary 1
,.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
ia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary.pdf 1
2. Some gelling agents are more soluble in cold water than in hot water. Poloxamers have
better solubility in cold water while bentonite and gelatin are more soluble in hot water.
3. Some gelling agents (carbomers) require a "neutralizer" or a pH adjusting chemical to
create the gel after the gelling agent has been wetted in the dispersing medium.
4. Most gelling agents require 24-48 hours to completely hydrate and reach maximum
viscosity and clarity.
5. Gelling agents are used in concentrations of 0.5% up to 10% depending on the agent.
6. It is easier to add the active drug before the gel is formed if the drug doesn't interfere
with the gel formation.
7. Only Carbopol® 934P, methylcellulose, hydroxypropyl methylcellulose, and sodium
carboxymethylcellulose are recommended for oral administration.
stuvia.com/user/gabrieluckyhttp10/22/2026,
.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
10/22/2026, 2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttp10/22/2026,
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2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyYear
2:06:01 AMhttps://www.stuvia.com/user/gabrieluckyhttps://www.stuvia.com/user/gabrieluckyhtt
1 Formulation Lecture - Summary 1
